Poly-(2,5-thiophendiyl)arsenic pentafluoride complexes

ABSTRACT

Reaction products of poly-(2,5-thiophendiyl) and arsenic pentafluoride. 
     The black complexes are insoluble solids. Due to their high electric conductivity they can be used as conductors of electric currents. Suitable applications are, e.g., sheet-form conductors for heating systems or electrodes for electrical batteries.

Continuation in part of Ser. No. 376,590, 5-10-82, abandoned.

This invention relates to poly-(2,5-thiophendiyl) doped with arsenic pentafluoride and to a process for the production thereof.

Poly-(2,5-thiophendiyl) is known and, according to Journal of Polymer Sci., Polymer Letters 18, 8 (1980), may be obtained by reacting 2,5-dibromothiophene with magnesium in the presence of nickel chloride in absolute tetrahydrofuran. The doping of this product with arsenic pentafluoride is new. The complex with arsenic pentafluoride is obtained by allowing gaseous arsenic pentafluoride to act on solid poly-(2,5-thiophendiyl) for from a few minutes to several days in the absence of air at about +10°to +30° C., i.e. in the absence of oxygen and moisture and under pressures from 0.1 mbar to atmospheric pressure

Instead of starting with poly-(2.5-thiophendiyl), it is possible, and preferred, to treat thiophene or 2,2'-dithienyl or mixtures thereof with arsenic pentafluoride under the above-described conditions.

In every case, black insoluble polymeric complexes are obtained (in the form of powders or even films on the walls of the vessel) which do not melt at temperatures of up to 360° C. and which have an electric conductivity of up to δ298 K-0.02Ω⁻¹ . cm⁻¹ (as measured at P=1500 Kp . cm⁻² in the range from 20° to 120° C. [for the measuring technique, see J. Danhauser, G. Manecke, Makromol. Chem. 84, 238 (1964)].

The black complexes are insoluble solids. Due to their high electric conductivity they can be used as conductors of electric currents. Suitable applications are, e.g., sheet-form conductors for heating systems or electrodes for electrical batteries.

EXAMPLES 1. Starting products:

1=poly-(2,5-thiophendiyl) obtained from 2,5- dibromothiophene in accordance with J. Polymer Sci., Polymer Letters 18, 8 (1980); electrical conductivity δ298 K=5.7 . 10⁻¹¹ Ω⁻¹. cm⁻¹ (cf. Table 1, No. 1).

2=2,2'-dithienyl

3=thiophene.

2. Production Process

The starting material was placed in a vacuum and arsenic pentafluoride allowed to act on it at room temperature for the periods under the pressures in Table 1. Black complexes having melting points above 360° C. were obtained in every case, the electrical data thereof being shown in Table 1:

                                      TABLE 1                                      __________________________________________________________________________     Poly-(2,5-thiophendiyl)-AsF.sub.5 --complexes                                          AsF.sub.5,                                                                Starting                                                                            pressure                                                                            Time                                                                              σ 298K                                                                          σ°                                                                       E                                                No.                                                                               material                                                                            (Torr)                                                                              (h)                                                                               [Ω.sup.-1 · cm.sup.-1 ]                                                [Ω.sup.-1 · cm.sup.-1 ]                                                [eV]                                             __________________________________________________________________________     1  1    --   -- 5.7 · 10.sup.-11(b)                                                          2.4 · 10.sup.-5                                                              0.66                                             2  1     40  24 5.9 · 10.sup.-8                                                              2.7 · 10.sup.+1                                                              1.02                                             3  1    200  24 5.4 · 10.sup.-4                                                              6.4 · 10.sup.-1                                                              0.36                                             4  1    450  24 1.4 · 10.sup.-3                                                              1.6 · 10.sup.-1                                                              0.24                                             5  2    450  60 7.1 · 10.sup.-4                                                              2.9 · 10.sup.-2                                                              0.19                                             6  2    650  24 5.5 · 10.sup.-4                                                              5.0 · 10.sup.-3                                                              0.11                                             7       650  24 1.7 · 10.sup.-3                                                              2.5 · 10.sup.-2                                                              0.14 =  No. 6, treated                            8.sup.(a)                                                                        2    450  60 1.5 · 10.sup.-5                                                              5.2 · 10.sup.-2                                                              0.42   with NH.sub.4 OH and                      9  3    200  24 6.9 · 10.sup.-8                                                              1.9 · 10°                                                             0.88   redoped with                              10 3    300  24 6.5 · 10.sup.-7                                                              1.7 · 10.sup.-2                                                              0.52   AsF.sub.5                                 11              1.2 · 10.sup.-15                                                             6.6 · 10.sup.+1                                                              1.98 = No. 10, treated                           12 3    450  60 2.1 · 10.sup.-2                                                              4.8 · 10.sup.-2                                                              0.04   for 3 days with                           13 3    650  48 7.4 · 10.sup.-4                                                              2.2 · 10.sup.-2                                                              0.17   H.sub.2 O                                  14.sup.(a)                                                                       3    650  48 1.1 · 10.sup.-3                                                              2.2 · 10.sup.-3                                                              0.04                                             __________________________________________________________________________      .sup.(a) A film formed on the walls of the vessel (No. 8 = 0.0046 cm           thick; No. 14 = 0.004 cm thick)                                                .sup.(b) 291K = 5.3 · 10.sup.-11 Ω .sup.-1 ·           cm.sup.-1 (cf. T. Yamamoto, K. Sanechika, A. Yamamoto, J. Polymer Sci.,        Polymer Letters 18,8 (1980)).                                             

I claim:
 1. Poly-(2,5-thiophendiyl) doped with arsenic pentafluoride.
 2. A process for the production of poly-(2,5-thiophendiyl) doped with arsenic pentafluoride, wherein poly-(2,5-thiophendiyl) or 2,2'-dithienyl or thiophene or mixtures of 2,2'-dithienyl and thiophene is/are treated with gaseous arsenic pentafluoride in the absence of oxygen and moisture at +10° to +30° C. under pressures of from 0.1 mbar to atmospheric pressure. 